The present invention relates to a system for communication using a broadcast audio signal being played over the speaker of a television or radio and an unconnected device located anywhere within the normal listening area. Until now, no system existed for communication through a television broadcast signal to a device locatable anywhere in general proximity to a television or radio receiver.
A remote system for playing a game while watching a live sports event on television is described in Fascenda et al., U.S. Pat. No. 4,592,546. However, the game control information does not come through the television receiver. Rather, it requires employment of sub-carrier techniques, and installation of special receivers capable of detecting out-band signals. Since the information is part of a separate signal, it cannot be taped for later use and must be produced by a live person anew upon each broadcast.
A system for playing games on a television picture screen is presented in Baer U.S. Pat. No. re. 32,305. It utilizes flashing "dots" to mean various things. The flashing dots appear in plain view on the screen, each representing an answer to a multiple choice question. The dot representing the correct answer has an odd number of flashes. The others have an even number. A gun with a photoelectric cell is aimed at a dot to choose the corresponding answer. The gun will light an indicator light if it detects a dot flashing an odd number of times. Alternatively, the photoelectric cell can be attached directly to a predetermined spot on the television screen.
The system of Baer has a number of shortcomings. It requires disturbing the normal television picture by the addition of brightly flashing lights in a specially dedicated portion of the screen. It also requires that the detecting device be aimed or placed directly on a predetermined spot of the television screen. It uses the video portion of a broadcast and so is inoperative with other communication receivers such as radios.
An audio signal is used by cable television networks to switch on and off a machine located at their local television stations. The signal consists of sequential Touch-Tones and it is used to turn on a tape player to broadcast a commercial advertisement. Another signal turns the player off, returning the broadcast to the network program.
This arrangement is limited in at least the following three ways. First, it employs only two different signals to simply turn a machine on or off. No significant information is communicated. Second, it is used only in-house, for the network to switch on its own station's machine. The station receives the signal from its source at the network over enormous dish antennae. Third, the signal is discernible to viewers, even though they have no use for it. The network momentarily blanks out the audio portion of its broadcast and instead plays multiple sequential Touch-Tones alone at a high volume.
Accordingly, it is an objective of the present invention to provide a communication system useful to anyone listening to a television or radio receiver. It is a further objective that encoded information employed in such a system be susceptible of taping.
It is yet another objective of the present invention to provide such a system that does not require disturbing or dedicating a portion of a normal television picture. It is another objective to provide a device for receiving information from a communication receiver, that need not be aimed at or attached in any way to the receiver. It is another objective that such system employ the audio portion of a broadcast so it is useful with radios as well as television.
It is still another objective of the present invention to use an audio signal to communicate various information. It is another objective that such communication be to the public and take place through the speaker of an ordinary television or radio receiver such that the recipient of the information need not have special receiving equipment. It is another objective that such signal be substantially indiscernible to listeners.